Class DataOutputStream

protected int written

This is the total number of bytes that have been written to the stream by this object instance.

public DataOutputStream(OutputStream out)

This method initializes an instance of DataOutputStream to write its data to the specified underlying OutputStream

Parameters:

out - The subordinate OutputStream to which this object will write

public void flush()
            throws IOException

This method flushes any unwritten bytes to the underlying stream.

Specified by:

flush in interface Flushable

Overrides:

flush in interface FilterOutputStream

Throws:

IOException - If an error occurs.

public final int size()

This method returns the total number of bytes that have been written to the underlying output stream so far. This is the value of the written instance variable

Returns:

The number of bytes written to the stream.

public void write(byte[] buf,
                  int offset,
                  int len)
            throws IOException

This method writes len bytes from the specified byte array buf starting at position offset into the buffer to the underlying output stream.

Specified by:

write in interface DataOutput

Overrides:

write in interface FilterOutputStream

Parameters:

buf - The byte array to write from.

offset - The index into the byte array to start writing from.

len - The number of bytes to write.

Throws:

IOException - If an error occurs.

public void write(int value)
            throws IOException

This method writes the specified byte (passed as an int) to the underlying output stream.

Specified by:

write in interface DataOutput

Overrides:

write in interface FilterOutputStream

Parameters:

value - The byte to write, passed as an int.

Throws:

IOException - If an error occurs.

public final void writeBoolean(boolean value)
            throws IOException

This method writes a Java boolean value to an output stream. If value is true, a byte with the value of 1 will be written, otherwise a byte with the value of 0 will be written. The value written can be read using the readBoolean method in DataInput.

Specified by:

writeBoolean in interface DataOutput

Parameters:

value - The boolean value to write to the stream

Throws:

IOException - If an error occurs

See Also:

DataInput.readBoolean()

public final void writeByte(int value)
            throws IOException

This method writes a Java byte value to an output stream. The byte to be written will be in the lowest 8 bits of the int value passed. The value written can be read using the readByte or readUnsignedByte methods in DataInput.

Specified by:

writeByte in interface DataOutput

Parameters:

value - The byte to write to the stream, passed as the low eight bits of an int.

Throws:

IOException - If an error occurs

See Also:

DataInput.readByte(), DataInput.readUnsignedByte()

public final void writeBytes(String value)
            throws IOException

This method writes all the bytes in a String out to the stream. One byte is written for each character in the String. The high eight bits of each character are discarded, thus this method is inappropriate for completely representing Unicode characters.

Specified by:

writeBytes in interface DataOutput

Parameters:

value - The String to write to the stream

Throws:

IOException - If an error occurs

public final void writeChar(int value)
            throws IOException

This method writes a Java char value to an output stream. The char to be written will be in the lowest 16 bits of the int value passed. These bytes will be written "big endian". That is, with the high byte written first in the following manner:

byte0 = (byte)((value & 0xFF00) >> 8);
byte1 = (byte)(value & 0x00FF);

The value written can be read using the readChar method in DataInput.

Specified by:

writeChar in interface DataOutput

Parameters:

value - The char value to write, passed as an int.

Throws:

IOException - If an error occurs

See Also:

DataInput.readChar()

public final void writeChars(String value)
            throws IOException

This method writes all the characters of a String to an output stream as an array of char's. Each character is written using the method specified in the writeChar method.

Specified by:

writeChars in interface DataOutput

Parameters:

value - The String to write to the stream

Throws:

IOException - If an error occurs

See Also:

writeChar(char)

public final void writeDouble(double value)
            throws IOException

This method writes a Java double value to the stream. This value is written by first calling the method Double.doubleToLongBits to retrieve an long representing the floating point number, then writing this long value to the stream exactly the same as the writeLong() method does. The value written can be read using the readDouble method in DataInput.

Specified by:

writeDouble in interface DataOutput

Parameters:

value - The double value to write to the stream

Throws:

IOException - If an error occurs

See Also:

writeLong(long), DataInput.readDouble(), Double.doubleToLongBits(double)

public final void writeFloat(float value)
            throws IOException

This method writes a Java float value to the stream. This value is written by first calling the method Float.floatToIntBits to retrieve an int representing the floating point number, then writing this int value to the stream exactly the same as the writeInt() method does. The value written can be read using the readFloat method in DataInput.

Specified by:

writeFloat in interface DataOutput

Parameters:

value - The float value to write to the stream

Throws:

IOException - If an error occurs

See Also:

writeInt(int), DataInput.readFloat(), Float.floatToIntBits(float)

public final void writeInt(int value)
            throws IOException

This method writes a Java int value to an output stream. The 4 bytes of the passed value will be written "big endian". That is, with the high byte written first in the following manner:

byte0 = (byte)((value & 0xFF000000) >> 24);
byte1 = (byte)((value & 0x00FF0000) >> 16);
byte2 = (byte)((value & 0x0000FF00) >> 8);
byte3 = (byte)(value & 0x000000FF);

The value written can be read using the readInt method in DataInput.

Specified by:

writeInt in interface DataOutput

Parameters:

value - The int value to write to the stream

Throws:

IOException - If an error occurs

See Also:

DataInput.readInt()

public final void writeLong(long value)
            throws IOException

This method writes a Java long value to an output stream. The 8 bytes of the passed value will be written "big endian". That is, with the high byte written first in the following manner:

byte0 = (byte)((value & 0xFF00000000000000L) >> 56);
byte1 = (byte)((value & 0x00FF000000000000L) >> 48);
byte2 = (byte)((value & 0x0000FF0000000000L) >> 40);
byte3 = (byte)((value & 0x000000FF00000000L) >> 32);
byte4 = (byte)((value & 0x00000000FF000000L) >> 24);
byte5 = (byte)((value & 0x0000000000FF0000L) >> 16);
byte6 = (byte)((value & 0x000000000000FF00L) >> 8);
byte7 = (byte)(value & 0x00000000000000FFL);

The value written can be read using the readLong method in DataInput.

Specified by:

writeLong in interface DataOutput

Parameters:

value - The long value to write to the stream

Throws:

IOException - If an error occurs

See Also:

DataInput.readLong()

public final void writeShort(int value)
            throws IOException

This method writes a Java short value to an output stream. The char to be written will be in the lowest 16 bits of the int value passed. These bytes will be written "big endian". That is, with the high byte written first in the following manner:

byte0 = (byte)((value & 0xFF00) >> 8);
byte1 = (byte)(value & 0x00FF);

The value written can be read using the readShort and readUnsignedShort methods in DataInput.

Specified by:

writeShort in interface DataOutput

Parameters:

value - The short value to write to the stream, passed as an int.

Throws:

IOException - If an error occurs

See Also:

DataInput.readShort(), DataInput.readUnsignedShort()

public final void writeUTF(String value)
            throws IOException

This method writes a Java String to the stream in a modified UTF-8 format. First, two bytes are written to the stream indicating the number of bytes to follow. Note that this is the number of bytes in the encoded String not the String length. Next come the encoded characters. Each character in the String is encoded as either one, two or three bytes. For characters in the range of \u0001 to <\u007F>, one byte is used. The character value goes into bits 0-7 and bit eight is 0. For characters in the range of \u0080 to \u007FF, two bytes are used. Bits 6-10 of the character value are encoded bits 0-4 of the first byte, with the high bytes having a value of "110". Bits 0-5 of the character value are stored in bits 0-5 of the second byte, with the high bits set to "10". This type of encoding is also done for the null character \u0000. This eliminates any C style NUL character values in the output. All remaining characters are stored as three bytes. Bits 12-15 of the character value are stored in bits 0-3 of the first byte. The high bits of the first bytes are set to "1110". Bits 6-11 of the character value are stored in bits 0-5 of the second byte. The high bits of the second byte are set to "10". And bits 0-5 of the character value are stored in bits 0-5 of byte three, with the high bits of that byte set to "10". The value written can be read using the readUTF method in DataInput.

Specified by:

writeUTF in interface DataOutput

Parameters:

value - The String to write to the output in UTF format

Throws:

IOException - If an error occurs

See Also:

DataInput.readUTF()